This invention relates to a series of phenylalanine derivatives, to compositions containing them, to processes for their preparation, and to their use in medicine.
Over the last few years it has become increasingly clear that the physical interaction of inflammatory leukocytes with each other and other cells of the body plays an important role in regulating immune and inflammatory responses [Springer, T A. Nature, 346, 425, (1990); Springer, T. A. Cell 76, 301, (1994)]. Many of these interactions are mediated by specific cell surface molecules collectively referred to as cell adhesion molecules.
The adhesion molecules have been sub-divided into different groups on the basis of their structure. One family of adhesion molecules which is believed to play a particularly important role in regulating immune and inflammatory responses is the integrin family. This family of cell surface glycoproteins has a typical non-covalently linked heterodimer structure. At least 14 different integrin alpha chains and 8 different integrin beta chains have been identified [Sonnenberg, A. Current Topics in Microbiology and Immunology, 184, 7, (1993)]. The members of the family are typically named according to their heterodimer composition although trivial nomenclature is widespread in this field. Thus the integrin termed xcex14xcex21 consists of the integrin alpha 4 chain associated with the integrin beta 1 chain, but is also widely referred to as Very Late Antigen 4 or VLA4. Not all of the potential pairings of integrin alpha and beta chains have yet been observed in nature and the integrin family has been subdivided into a number of subgroups based on the pairings that have been recognised [Sonnenberg, A. ibid].
The importance of cell adhesion molecules in human leukocyte function has been further highlighted by a genetic deficiency disease called Leukocyte Adhesion Deficiency (LAD) in which one of the families of leukocyte integrins is not expressed [Marlin, S. D. et al J. Exp. Med. 164, 855 (1986)]. Patients with this disease have a reduced ability to recruit leukocytes to inflammatory sites and suffer recurrent infections which in extreme cases may be fatal.
The potential to modify adhesion molecule function in such a way as to beneficially modulate immune and inflammatory responses has been extensively investigated in animal models using specific monoclonal antibodies that block various functions of these molecules [e.g. Issekutz, T. B. J. Immunol. 3394, (1992); Li, Z. et al Am. J. Physiol. 263, L723, (1992); Binns, R. M. et al J. Immunol. 157, 4094, (1996)]. A number of monoclonal antibodies which block adhesion molecule function are currently being investigated for their therapeutic potential in human disease.
One particular integrin subgroup of interest involves the xcex14 chain which can pair with two different beta chains xcex21 and xcex17 [Sonnenberg, A. ibid] The xcex14xcex21 pairing occurs on many circulating leukocytes (for example lymphocytes, monocytes and eosinophils) although it is absent or only present at low levels on circulating neutrophils. xcex14xcex21 binds to an adhesion molecule (Vascular Cell Adhesion Molecule-1 also known as VCAM-1) frequently up-regulated on endothelial cells at sites of inflammation [Osborne, L. Cell, 62, 3 (1990)]. The molecule has also been shown to bind to at least three sites in the matrix molecule fibronectin [Humphries, M. J. et al. Ciba Foundation Symposium, 189, 177, (1995)]. Based on data obtained with monoclonal antibodies in animal models it is believed that the interaction between xcex14xcex21 and ligands on other cells and the extracellular matrix plays an important role in leukocyte migration and activation [Yednock, T. A et al, Nature, 356, 63, (1992); Podolsky, D. K. et al. J. Clin. Invest. 92, 373, (1993); Abraham, W. M. et al. J. Clin. Invest. 93, 776, (1994)].
The integrin generated by the pairing of xcex14 and xcex27 has been termed LPAM-1 [Holzmann, B and Weissman, I. EMBO J. 8, 1735, (1989)] and like xcex14xcex21, binds to VCAM-1 and fibronectin. In addition, xcex14xcex27 binds to an adhesion molecule believed to be involved in the homing of leukocytes to mucosal tissue termed MAdCAM-1 [Berlin, C. et al, Cell, 74, 185, (1993)]. The interaction between xcex14xcex27 and MAdCAM-1 may also be important at sites of inflammation outside of mucosal tissue [Yang, X-D. et al, PNAS, 91, 12604 (1994)].
Regions of the peptide sequence recognised by xcex14xcex21 and xcex14xcex27 when they bind to their ligands have been identified. xcex14xcex21 seems to recognise LDV, IDA or REDV peptide sequences in fibronectin and a QIDSP sequence in VCAM-1 [Humphries, M. J. et al, ibid] whilst xcex14xcex27 recognises a LDT sequence in MAdCAM-1 [Briskin, M. J. et al, J. Immunol. 156, 719, (1996)]. There have been several reports of inhibitors of these interactions being designed from modifications of these short peptide sequences [Cardarelli, P. M. et al J. Biol. Chem. 26, 18668, (1994); Shroff, H. N. Bioorganic. Med. Chem. Lett. 6, 2495, (1996); Vanderslice, P. J. Immunol. 158, 1710, (1997)]. It has also been reported that a short peptide sequence derived from the xcex14xcex21 binding site in fibronectin can inhibit a contact hypersensitivity reaction in a trinitrochlorobenzene sensitised mouse [Ferguson, T. A. et al, PNAS 8, 8072, (1991)].
Since the alpha 4 subgroup of integrins are predominantly expressed on leukocytes their inhibition can be expected to be beneficial in a number of immune or inflammatory disease states. However, because of the ubiquitous distribution and wide range of functions performed by other members of the integrin family it is very important to be able to identify selective inhibitors of the alpha 4 subgroup.
We have now found a group of compounds which are potent and selective inhibitors of xcex14 integrins. Members of the group are able to inhibit xcex14 integrins such as xcex14xcex21 and/or xcex14xcex27 at concentrations at which they generally have no or minimal inhibitory action on xcex1 integrins of other subgroups. The compounds are thus of use in medicine, for example in the prophylaxis and treatment of immune or inflammatory disorders as described hereinafter.
Thus according to one aspect of the invention we provide a compound of formula (1) 
wherein
Ar1 is an aromatic or heteroaromatic group;
R1, R2, R3, R4 and R5 which may be the same or different is each an atom or group xe2x80x94L2(Alk3)tL3(R7)u in which L2 and L3 which may be the same or different is each a covalent bond or a linker atom or group, t is zero or the integer 1, u is an integer 1, 2 or 3, Alk3 is an aliphatic or heteroaliphatic chain and R7 is a hydrogen or halogen atom or a group selected from alkyl, xe2x80x94OR8 [where R8 is a hydrogen atom or an optionally substituted alkyl group], xe2x80x94SR8, xe2x80x94NR8R9 [where R9 is as just defined for R8 and may be the same or different], xe2x80x94NO2, xe2x80x94CN, xe2x80x94CO2R8, xe2x80x94SO3H, xe2x80x94SOR8, xe2x80x94SO2R8, xe2x80x94OCO2R8, xe2x80x94CONR8R9, xe2x80x94OCONR8R9, xe2x80x94CSNR8R9, xe2x80x94COR8, xe2x80x94OCOR8, xe2x80x94N(R8)COR9, xe2x80x94N(R8)CSR9, xe2x80x94SO2N(R8)(R9), xe2x80x94N(R8)SO2 R9, xe2x80x94N(R8)CON(R9)(R10), [where R10 is a hydrogen atom or an optionally substituted alkyl group] xe2x80x94N(R8)CSN(R9)(R10) or xe2x80x94N(R8)SO2N(R9)(R10);
Alk1 is an optionally substituted aliphatic or heteroaliphatic chain;
L1 is a covalent bond or a linker atom or group;
Alk2 is a straight or branched alkylene chain;
m is zero or an integer 1;
R6 is a hydrogen atom or a methyl group;
r is zero or the integer 1;
R is a carboxylic acid (xe2x80x94CO2H) or a derivative thereof;
Ra is a hydrogen atom or a methyl group;
g is zero or the integer 1;
Ar2 is an optionally substituted aromatic or heteroaromatic group;
and the salts, solvates, hydrates and N-oxides thereof.
It will be appreciated that compounds of formula (1) may have one or more chiral centres, and exist as enantiomers or diastereomers. The invention is to be understood to extend to all such enantiomers, diastereomers and mixtures thereof, including racemates. Formula (1) and the formulae hereinafter are intended to represent all individual isomers and mixtures thereof, unless stated or shown otherwise.
In the compounds of formula (1), derivatives of the carboxylic acid group R include carboxylic acid esters and amides. Particular esters and amides include xe2x80x94CO2Alk5 and xe2x80x94CONR8R9 groups as described herein.
In general, the substituents R1, R2 and R3 in compounds of the invention may be positioned on any available carbon atom, or, when present, nitrogen atom in the aromatic or heteroaromatic group represented by Ar1.
When Alk1 is present in compounds of formula (1) as an optionally substituted aliphatic chain it may be an optionally substituted C1-10 aliphatic chain. Particular examples include optionally substituted straight or branched chain C1-6 alkyl, C2-6 alkenyl, or C2-6 alkynyl chains.
Heteroaliphatic chains represented by Alk1 include the aliphatic chains just described but with each chain additionally containing one, two, three or four heteroatoms or heteroatom-containing groups. Particular heteroatoms or groups include atoms or groups L4 where L4 is as defined above for L1 when L1 is a linker atom or group. Each L4 atom or group may interrupt the aliphatic chain, or may be positioned at its terminal carbon atom to connect the chain to an adjoining atom or group.
Particular examples of aliphatic chains represented by Alk1 include optionally substituted xe2x80x94CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94CH(CH3)xe2x80x94, xe2x80x94C(CH3)2xe2x80x94, xe2x80x94(CH2)2CH2xe2x80x94, xe2x80x94CH(CH3 )CH2xe2x80x94, xe2x80x94(CH2)3CH2xe2x80x94, xe2x80x94CH(CH3)CH2CH2xe2x80x94, xe2x80x94CH2CH(CH3)CH2xe2x80x94, xe2x80x94C(CH3)2CH2xe2x80x94, xe2x80x94(CH2)4CH2xe2x80x94, xe2x80x94(CH2)5CH2xe2x80x94, xe2x80x94CHCHxe2x80x94, xe2x80x94CHCHCH2xe2x80x94, xe2x80x94CH2CHCHxe2x80x94, xe2x80x94CHCHCH2CH2xe2x80x94, xe2x80x94CH2CHCHCH2xe2x80x94, xe2x80x94(CH2)2CHCHxe2x80x94, xe2x80x94CCxe2x80x94, xe2x80x94CCCH2xe2x80x94, xe2x80x94CH2CCxe2x80x94, xe2x80x94CCCH2CH2xe2x80x94, xe2x80x94CH2CCCH2xe2x80x94, or xe2x80x94(CH2)2CCxe2x80x94 chains. Where appropriate each of said chains may be optionally interrupted by one or two atoms and/or groups L4 to form an optionally substituted heteroaliphatic chain. Particular examples include optionally substituted L4CH2xe2x80x94, xe2x80x94CH2L4CH2xe2x80x94, xe2x80x94L4(CH2)2xe2x80x94, xe2x80x94CH2L4(CH2)2xe2x80x94, xe2x80x94(CH2)2L4CH2xe2x80x94, xe2x80x94L4(CH2)3xe2x80x94 and xe2x80x94(CH2)2L4(CH2)2xe2x80x94 chains. The substituents which may be present on aliphatic or heteroaliphatic chains represented by Alk1 include one, two, three or more substituents where each substituent may be the same or different and is selected from halogen atoms, e.g. fluorine, chlorine, bromine or iodine atoms, or C1-6alkoxy, e.g. methoxy or ethoxy, thiol, C1-6alkylthio e.g. methylthio or ethylthio, amino or substituted amino groups. Substituted amino groups include xe2x80x94NHR12 and xe2x80x94N(R12)2 groups where R12 is an optionally substituted straight or branched alkyl group as defined below for R11. Where two R12 groups are present these may be the same or different. Particular examples of substituted chains represented by Alk1 include those specific chains just described substituted by one, two, or three halogen atoms such as fluorine atoms, for example chains of the type xe2x80x94CH(CF3)xe2x80x94, xe2x80x94C(CF3 )2xe2x80x94, xe2x80x94CH2CH(CF3)xe2x80x94, xe2x80x94CH2 C(CF3)2xe2x80x94, xe2x80x94CH(CF3 )xe2x80x94 and xe2x80x94C(CF 3)2CH2.
Alk2 in the compounds of the invention may be for example a straight or branched C1-3alkylene chain. Particular examples include xe2x80x94CH2xe2x80x94, xe2x80x94CH(CH3)xe2x80x94 and xe2x80x94(CH2)2xe2x80x94.
When in the compounds of formula (1) L1, L2 and/or L3 is present as a linker atom or group it may be any divalent linking atom or group. Particular examples include xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 atoms or xe2x80x94C(O)xe2x80x94, xe2x80x94C(O)Oxe2x80x94, xe2x80x94OC(O)xe2x80x94, xe2x80x94C(S)xe2x80x94, xe2x80x94S(O)xe2x80x94, xe2x80x94S(O)2xe2x80x94, xe2x80x94N(R11)xe2x80x94 [where R11 is a hydrogen atom or an optionally substituted alkyl group], xe2x80x94CON(R11)xe2x80x94, xe2x80x94OC(O)N(R11)xe2x80x94, xe2x80x94CSN(R11)xe2x80x94, xe2x80x94N(R11)COxe2x80x94, xe2x80x94N(R11)C(O)Oxe2x80x94, xe2x80x94N(R11)CSxe2x80x94, xe2x80x94S(O)2N(R11)xe2x80x94, xe2x80x94N(R11)S(O)2xe2x80x94, xe2x80x94N(R11)CON(R11)xe2x80x94, xe2x80x94N(R11)CSN(R11)xe2x80x94, or xe2x80x94N(R11)SO2N(R11)xe2x80x94 groups. Where the linker group contains two R11 substituents, these may be the same or different.
When R7, R8, R9, R10 and/or R11 in the compounds of formula (1) is an alkyl group it may be a straight or branched C1-6alkyl group, e.g. a C1-3alkyl group such as a methyl or ethyl group. Optional substituents which may be present on such groups include for example one, two or three substituents which may be the same or different selected from halogen atoms, for example fluorine, chlorine, bromine or iodine atoms, or hydroxy or C1-6alkoxy e.g. methoxy or ethoxy groups.
When Alk3 is present in the compounds of formula (1) as an aliphatic or heteroaliphatic chain it may be for example any of the above-mentioned C1-10aliphatic or heteroaliphatic chains described for Alk1.
Halogen atoms represented by R7 in compounds of the invention include fluorine, chlorine, bromine, or iodine atoms.
Examples of the substituents represented by R1, R2, R3, R4 and R5 in compounds of formula (1) include atoms or groups xe2x80x94L2Alk3L3R7, xe2x80x94L2Alk3R7, xe2x80x94L2R7, xe2x80x94Alk3R7 and xe2x80x94R7 wherein L2, Alk3, L3 and R7 are as defined above. Particular examples of such substituents include xe2x80x94L2CH2L3R7, xe2x80x94L2CH(CH3)L3R7, xe2x80x94L2CH(CH2)2L3R7, xe2x80x94L2CH2R7, xe2x80x94L2CH(CH3)R7, L2(CH2)2R7, xe2x80x94CH2R7, xe2x80x94CH(CH3)R7 and xe2x80x94(CH2)2R7 groups.
Thus each of R1, R2, R3, R4 and R5 in compounds of the invention may be for example a hydrogen atom, a halogen atom, e.g. a fluorine, chlorine, bromine or iodine atom, or a C1-6alkyl, e.g. methyl, ethyl, n-propyl, i-propyl, n-butyl or t-butyl, C1-6alkylamino, e.g. methylamino or ethylamino, C1-6hydroxyalkyl, e.g. hydroxymethyl or hydroxyethyl, carboxyC1-6alkyl, e.g. carboxyethyl, C1-6alkylthio e.g. methylthio or ethylthio, carboxyC1-6alkylthio, e.g. carboxymethylthio, 2-carboxyethylthio or 3-carboxy-propylthio, C1-6alkoxy, e.g. methoxy or ethoxy, C6-12arylC1-6alkyloxy e.g. benzyloxy, hydroxyC1-6alkoxy, e.g. 2-hydroxyethoxy, haloC1-6alkyl, e.g. trifluoromethyl, haloC1-6alkoxy, e.g. trifluoromethoxy, C1-6alkylamino, e.g. methylamino or ethylamino, amino (xe2x80x94NH2), aminoC1-6alkyl, e.g. aminomethyl or aminoethyl, C1-6dialkylamino, e.g. dimethylamino or diethylamino, C1-6alkylaminoC1-6alkyl, e.g. ethylaminoethyl, C1-6dialkylaminoC1-6alkyl, e.g. diethylaminoethyl, aminoC1-6alkoxy, e.g. aminoethoxy, C1-6alkylaminoC1-6alkoxy, e.g. methylaminoethoxy, C1-6dialkylaminoC1-6alkoxy, e.g. dimethylaminoethoxy, diethylaminoethoxy, diisopropylaminoethoxy, or dimethylaminopropoxy, nitro, cyano, amidino, hydroxyl (xe2x80x94OH), formyl [HC(O)xe2x80x94], carboxyl (xe2x80x94CO2H), xe2x80x94CO2Alk5 [where Alk5 is as defined below], C1-6 alkanoyl e.g. acetyl, thiol (xe2x80x94SH), thioC1-6alkyl, e.g. thiomethyl or thioethyl, thioC1-6alkylC6-12aryl e.g. thiobenzyl, sulphonyl (xe2x80x94SO3H), C1-6alkylsulphinyl e.g. methylsulphinyl, C1-6alkylsulphonyl, e.g. methylsulphonyl, aminosulphonyl (xe2x80x94SO2NH2), C1-6alkylaminosulphonyl, e.g. methylaminosulphonyl or ethylaminosulphonyl, C1-6dialkylaminosulphonyl, e.g. dimethylaminosulphonyl or diethylaminosulphonyl, phenylaminosulphonyl, carboxamido (xe2x80x94CONH2), C1-6alkylaminocarbonyl, e.g. methylaminocarbonyl or ethylaminocarbonyl, C1-6dialkylaminocarbonyl, e.g. dimethylaminocarbonyl or diethylaminocarbonyl, aminoC1-6alkylaminocarbonyl, e.g. aminoethylaminocarbonyl, C1-6dialkylaminoC1-6alkylaminocarbonyl, e.g. diethylaminoethylaminocarbonyl, aminocarbonylamino, C1-6alkylaminocarbonylamino, e.g. methylaminocarbonylamino or ethylaminocarbonylamino, C1-6dialkylaminocarbonylamino, e.g. dimethylaminocarbonylamino or diethylaminocarbonylamino, C1-6alkylaminocabonylC1-6alkylamino, e.g. methylaminocarbonylmethylamino, aminothiocarbonylamino, C1-6alkylaminothiocarbonylamino, e.g. methylaminothiocarbonylamino or ethylaminothiocarbonylamino, C1-6dialkylaminothiocarbonylamino, e.g. dimethylaminothiocarbonylamino or diethylaminothiocarbonylamino, C1-6alkylaminothiocarbonylC1-6alkylamino, e.g. ethylaminothiocarbonylmethylamino, C1-6alkylsulphonylamino, e.g. methylsulphonylamino or ethylsulphonylamino, C1-6dialkylsulphonylamino, e.g. dimethylsulphonylamino or diethylsulphonylamino, aminosulphonylamino (xe2x80x94NHSO2NH2), C1-6alkylaminosulphonylamino, e.g. methylaminosulphonylamino or ethylaminosulphonylamino, C1-6dialkylaminosulphonylamino, e.g. dimethylaminosulphonylamino or diethylaminosulphonylamino, C1-6alkanoylamino, e.g. acetylamino, aminoC1-6alkanoylamino e.g. aminoacetylamino, C1-6dialkylaminoC1-6alkanoylamino, e.g. dimethylaminoacetylamino, C1-6alkanoylaminoC1-6alkyl, e.g. acetylaminomethyl, C1-6alkanoylaminoC1-6alkylamino, e.g. acetamidoethylamino, C1-6alkoxycarbonylamino, e.g. methoxycarbonylamino, ethoxycarbonylamino or t-butoxycarbonylamino group.
Aromatic groups represented by the group Ar1 and/or Ar2 in compounds of the invention include for example monocyclic or bicyclic fused ring C6-12aromatic groups, such as phenyl, 1- or 2-naphthyl, 1- or 2-tetrahydronaphthyl, indanyl or indenyl groups. Aromatic groups represented by the group Ar2 may be optionally substituted by one, two, three or more R13 atoms or groups as defined below.
Heteroaromatic groups represented by the group Ar1 and/or Ar2 in the compounds of formula (1) include for example C1-9 heteroaromatic groups containing for example one, two, three or four heteroatoms selected from oxygen, sulphur or nitrogen atoms. In general, the heteroaromatic groups may be for example monocyclic or bicyclic fused ring heteroaromatic groups. Monocyclic heteroaromatic groups include for example five- or six-membered heteroaromatic groups containing one, two, three or four heteroatoms selected from oxygen, sulphur or nitrogen atoms. Bicyclic heteroaromatic groups include for example eight- to thirteen-membered fused-ring heteroaromatic groups containing one, two or more heteroatoms selected from oxygen, sulphur or nitrogen atoms.
Particular examples of heteroaromatic groups of these types include pyrrolyl, furyl, thienyl, imidazolyl, Nxe2x80x94C1-6alkylimidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyrazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, 1,3,4-thiadiazole, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, benzofuryl, [2,3-dihydro]benzofuryl, benzothienyl, benzotriazolyl, indolyl, isoindolyl, benzimidazolyl, imidazo[1,2-a]pyridyl, benzothiazolyl, benzoxazolyl, benzopyranyl, [3,4-dihydro]benzopyranyl, quinazolinyl, qunoxalinyl, naphthyridinyl, pyrido[3,4-b]pyridyl, pyrido[3,2-b]pyridyl, pyrido[4,3-b]-pyridyl, quinolinyl, isoquinolinyl, tetrazolyl, 5,6,7,8-tetrahydroquinolinyl, 5,6,7,8-tetrahydroisoquinolinyl, and imidyl, e.g. succinimidyl, phthalimidyl, or naphthalimidyl such as 1,8-naphthalimidyl.
Optional substituents which may be present on the aromatic or heteroaromatic groups represented by Ar2 include one, two, three or more substituents, each selected from an atom or group R13 in which R13 is xe2x80x94R13a or xe2x80x94Alk4(R13a)m, where R13a is a halogen atom, or an amino (xe2x80x94NH2), substituted amino, nitro, cyano, amidino, hydroxyl (xe2x80x94OH), substituted hydroxyl, formyl, carboxyl (xe2x80x94CO2H), esterified carboxyl, thiol (xe2x80x94SH), substituted thiol, xe2x80x94COR14 [where R14 is an xe2x80x94Alk3(R13a)m, aryl or heteroaryl group], xe2x80x94CSR14, xe2x80x94SO3H, xe2x80x94SO2R14, xe2x80x94SO2NH2, xe2x80x94SO2NHR14, SO2N(R14)2, xe2x80x94CONH2, xe2x80x94CSNH2, xe2x80x94CONHR14, xe2x80x94CSNHR14, xe2x80x94CON[R14]2, xe2x80x94CSN(R14)2, xe2x80x94N(R12)SO2R14, xe2x80x94N(SO2R14)2, xe2x80x94NH2(R11)SO2NH2, xe2x80x94N(R11)SO2NHR14, xe2x80x94N(R11)SO2N(R14)2, xe2x80x94N(R11)COR14, xe2x80x94N(R11)CON(R14)2, xe2x80x94N(R11)CSN(R14)2, xe2x80x94N(R11)CSR14, xe2x80x94N(R11)C(O)OR14, xe2x80x94SO2NHet1, [where xe2x80x94NHet1 is an optionally substituted C5-7cyclicamino group optionally containing one or more other xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 atoms or xe2x80x94N(R11)xe2x80x94, xe2x80x94C(O)xe2x80x94 or xe2x80x94C(S)xe2x80x94 groups ], xe2x80x94CONHet1, xe2x80x94CSNHet1, xe2x80x94N(R11)SO2NHet1, xe2x80x94N(R11)CONHet1, xe2x80x94N(R11)CSNHet1, xe2x80x94Het2, [where Het2 is an optionally substituted monocyclic C5-7carbocyclic group optionally containing one or more xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 atoms or xe2x80x94N(R11)xe2x80x94, xe2x80x94C(O)xe2x80x94 or xe2x80x94C(S)xe2x80x94 groups] xe2x80x94SO2N(R11)Het2, xe2x80x94CON(R11)Het2, xe2x80x94CSN(R11)Het2, xe2x80x94N(R11)CON(R11)Het2, xe2x80x94N(R11)CSN(R11)Het2, aryl or heteroaryl group; Alk4 is a straight or branched C1-6alkylene, C2-6alkenylene or C2-6alkynylene chain, optionally interrupted by one, two or three xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 atoms or xe2x80x94S(O)n [where n is an integer 1 or 2] or xe2x80x94N(R15)xe2x80x94 groups [where R15 is a hydrogen atom or C1-6alkyl, e.g. methyl or ethyl group]; and m is zero or an integer 1, 2 or 3. It will be appreciated that when two R11 or R14 groups are present in one of the above substituents, the R11 or R14 groups may be the same or different.
When in the group xe2x80x94Alk4(R13a)m m is an integer 1, 2 or 3, it is to be understood that the substituent or substituents R13a may be present on any suitable carbon atom in xe2x80x94Alk4. Where more than one R13a substituent is present these may be the same or different and may be present on the same or different atom in xe2x80x94Alk4. Clearly, when m is zero and no substituent R13a is present the alkylene, alkenylene or alkynylene chain represented by Alk4 becomes an alkyl, alkenyl or alkynyl group.
When R13a is a substituted amino group it may be for example a group xe2x80x94NHR14 [where R14 is as defined above] or a group xe2x80x94N(R14)2 wherein each R14 group is the same or different.
When R13a is a halogen atom it may be for example a fluorine, chlorine, bromine, or iodine atom.
When R13a is a substituted hydroxyl or substituted thiol group it may be for example a group xe2x80x94OR14 or a xe2x80x94SR14 or xe2x80x94SC(xe2x95x90NH)NH2 group respectively.
Esterified carboxyl groups represented by the group R13a include groups of formula xe2x80x94CO2Alk5 wherein Alk5 is a straight or branched, optionally substituted C1-8alkyl group such as a methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl or t-butyl group; a C6-12arylC1-8alkyl group such as an optionally substituted benzyl, phenylethyl, phenylpropyl, 1-naphthylmethyl or 2-naphthylmethyl group; a C6-12aryl group such as an optionally substituted phenyl, 1-naphthyl or 2-naphthyl group; a C6-12aryloxyC1-8alkyl group such as an optionally substituted phenyloxymethyl, phenyloxyethyl, 1-naphthyl-oxymethyl, or 2-naphthyloxymethyl group; an optionally substituted C1-8alkanoyloxyC1-8alkyl group, such as a pivaloyloxymethyl, propionyloxyethyl or propionyloxypropyl group; or a C6-12aroyloxyC1-8alkyl group such as an optionally substituted benzoyloxyethyl or benzoyloxy-propyl group. Optional substituents present on the Alk5 group include R13a substituents described above.
When Alk4 is present in or as a substituent it may be for example a methylene, ethylene, n-propylene, i-propylene, n-butylene, i-butylene, s-butylene, t-butylene, ethenylene, 2-propenylene, 2-butenylene, 3-butenylene, ethynylene, 2-propynylene, 2-butynylene or 3-butynylene chain, optionally interrupted by one, two, or three xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94, atoms or xe2x80x94S(O)xe2x80x94, xe2x80x94S(O)2xe2x80x94 or xe2x80x94N(R12)xe2x80x94 groups.
Aryl or heteroaryl groups represented by the groups R13a or R14 include mono- or bicyclic optionally substituted C6-12 aromatic or C1-9 heteroaromatic groups as described above for the group Ar2. The aromatic and heteroaromatic groups may be attached to the remainder of the compound of formula (1) by any carbon or hetero e.g. nitrogen atom as appropriate.
When xe2x80x94NHet1 or xe2x80x94Het2 forms part of a substituent R13 each may be for example an optionally substituted pyrrolidinyl, pyrazolidinyl, piperazinyl, morpholinyl, thiomorpholinyl, piperidinyl or thiazolidinyl group. Additionally Het2 may represent for example, an optionally substituted cyclopentyl or cyclohexyl group. Optional substituents which may be present on xe2x80x94NHet1or xe2x80x94Het2 include those R7 substituents described above.
Particularly useful atoms or groups represented by R13 include fluorine, chlorine, bromine or iodine atoms, or C1-6alkyl, e.g. methyl, ethyl, n-propyl, i-propyl, n-butyl or t-butyl, optionally substituted phenyl, pyridyl, pyrimidinyl, pyrrolyl, furyl, thiazolyl, or thienyl, morpholinyl, thiomorpholinyl, piperazinyl, pyrrolidinyl, piperidinyl, C1-6alkylamino, e.g. methylamino or ethylamino, C1-6hydroxyalkyl, e.g. hydroxymethyl or hydroxyethyl, carboxyC1-6alkyl, e.g. carboxyethyl, C1-6alkylthio e.g. methylthio or ethylthio, carboxyC1-6alkylthio, e.g. carboxymethylthio, 2-carboxyethylthio or 3-carboxypropylthio, C1-6alkoxy, e.g. methoxy or ethoxy, hydroxyC1-6alkoxy, e.g. 2-hydroxyethoxy, optionally substituted phenoxy, pyridyloxy, thiazolyoxy, phenylthio or pyridylthio, C5-7cycloalkoxy, e.g. cyclopentyloxy, haloC1-6alkyl, e.g. trifluoromethyl, haloC1-6alkoxy, e.g. trifluoromethoxy, C1-6alkylamino, e.g. methylamino or ethylamino or propylamino, optionally substituted C6-12arylC1-6alkylamino, e.g. benzylamino, fluorobenzylamino or hydroxyphenylethylamino, amino (-NH2), aminoC1-6alkyl, e.g. aminomethyl or aminoethyl, C1-6dialkylamino, e.g. dimethylamino or diethylamino, aminoC1-6alklamino e.g. aminomethylamino, aminoethylamino or aminopropylamino, Het1NC1-6alkylamino e.g. morpholinopropylamino, C1-6alkylaminoC1-6alkyl, e.g. ethylaminoethyl, C1-6dialkylaminoC1-6alkyl, e.g. diethylaminoethyl, aminoC1-6alkoxy, e.g. aminoethoxy, C1-6alkylaminoC1-6alkoxy, e.g. methylaminoethoxy, C1-6dialkylaminoC1-6alkoxy, e.g. dimethylaminoethoxy, diethylaminoethoxy, diisopropylaminoethoxy, or dimethylaminopropoxy, hydroxyC1-6alkylamino, e.g. hydroxyethylamino, hydroxypropylamino or hydroxybutylamino, imido, such as phthalimido or naphthalimido, e.g. 1,8-naphthalimido, nitro, cyano, amidino, hydroxyl (xe2x80x94OH), formyl [HC(O)xe2x80x94], carboxyl (xe2x80x94CO2H), xe2x80x94CO2Alk5 [where Alk5 is as defined above], C1-6 alkanoyl e.g. acetyl, propyryl or butyryl, optionally substituted benzoyl, thiol (xe2x80x94SH), thioC1-6alkyl, e.g. thiomethyl or thioethyl, xe2x80x94SC(xe2x95x90NH)NH2, sulphonyl (xe2x80x94SO3H), C1-6alkyl-sulphinyl, e.g. methylsulphinyl, ethylsulphinyl or propylsulphinyl, C1-6alkylsulphonyl, e.g. methylsulphonyl, ethylsulphonyl, propylsulphonyl, hexylsulphonyl or isobutylsulphonyl, aminosulphonyl (xe2x80x94SO2NH2), C1-6alkylaminosulphonyl, e.g. methylaminosulphonyl, ethylaminosulphonyl or propylaminocsulphonyl, C1-6dialkylaminosulphonyl, e.g. dimethylaminosulphonyl or diethylaminosulphonyl, optionally substituted phenylaminosulphonyl, carboxamido (xe2x80x94CONH2), C1-6alkylaminocarbonyl, e.g. methylaminocarbonyl, ethylaminocarbonyl or propylaminocarbonyl; C1-6dialkylaminocarbonyl, e.g. dimethylaminocarbonyl, diethylaminocarbonyl or dipropylaminocarbonyl, aminoC1-6alkylaminocarbonyl, e.g. aminoethylaminocarbonyl, C1-6dialkylaminoC1-6alkylaminocarbonyl, e.g. diethylaminoethylaminocarbonyl, aminocarbonylamino, C1-6alkylaminocarbonylamino, e.g. methylaminocarbonylamino or ethylaminocarbonylamino, C1-6dialkylaminocarbonylamino, e.g. dimethylaminocarbonylamino or diethylaminocarbonylamino, C1-6alkylaminocabonylC1-6alkylamino, e.g. methylaminocarbonylmethylamino, aminothiocarbonylamino, C1-6alkylaminothiocarbonylamino, e.g. methylaminothiocarbonylamino or ethylaminothiocarbonylamino, C1-6dialkylaminothiocarbonylamino, e.g. dimethylaminothiocarbonylamino or diethylaminothiocarbonylamino, C1-6alkylaminothiocarbonylC1-6alkylamino, e.g. ethylaminothiocarbonylmethylamino, xe2x80x94CONHC(xe2x95x90NH)NH2, C1-6alkylsulphonylamino, e.g. methylsulphonylamino or ethylsulphonylamino, C1-6dialkylsulphonylamino, e.g. dimethylsulphonylamino or diethylsulphonylamino, optionally substituted phenylsulphonylamino, aminosulphonylamino (xe2x80x94NHSO2NH2), C1-6alkylaminosulphonylamino, e.g. methylaminosulphonylamino or ethylaminosulphonylamino, C1-6dialkylaminosulphonylamino, e.g. dimethylaminosulphonylamino or diethylaminosulphonylamino, optionally substituted morpholinesulphonylamino or morpholinesulphonylC1-6alkyl-amino, optionally substituted phenylaminosulphonylamino, C1-6alkanoylamino, e.g. acetylamino, aminoC1-6alkanoylamino e.g. aminoacetylamino, C1-6dialkylamino C1-6alkanoylamino, e.g. dimethylaminoacetylamino, C1-6alkanoylamino C1-6alkyl, e.g. acetylaminomethyl, C1-6alkanoylaminoC1-6alkylamino, e.g. acetamidoethylamino, C1-6alkoxycarbonylamino, e.g. methoxycarbonylamino, ethoxycarbonylamino or t-butoxycarbonylamino or optionally substituted benzyloxy, pyridylmethoxy, thiazolylmethoxy, benzyloxycarbonylamino, benzyloxycarbonylaminoC1-6alkyl e.g. benzyloxycarbonylaminoethyl, thiobenzyl, pyridylmethylthio or thiazolylmethylthio groups.
Where desired, two R13 substituents may be linked together to form a cyclic group such as a cyclic ether, e.g. a C1-6alkylenedioxy group such as methylenedioxy or ethylenedioxy.
It will be appreciated that where two or more R13 substituents are present, these need not necessarily be the same atoms and/or groups. In general, the substituent(s) may be present at any available ring position in the aromatic or heteroaromatic group represented by Ar2.
The presence of certain substituents in the compounds of formula (1) may enable salts of the compounds to be formed. Suitable salts include pharmaceutically acceptable salts, for example acid addition salts derived from inorganic or organic acids, and salts derived from inorganic and organic bases.
Acid addition salts include hydrochlorides, hydrobromides, hydroiodides, alkylsulphonates, e.g. methanesulphonates, ethanesulphonates, or isothionates, arylsulphonates, e.g. p-toluenesulphonates, besylates or napsylates, phosphates, sulphates, hydrogen sulphates, acetates, trifluoroacetates, propionates, citrates, maleates, fumarates, malonates, succinates, lactates, oxalates, tartrates and benzoates.
Salts derived from inorganic or organic bases include alkali metal salts such as sodium or potassium salts, alkaline earth met al salts such as magnesium or calcium salts, and organic amine salts such as morpholine, piperidine, dimethylamine or diethylamine salts.
Particularly useful salts of compounds according to the invention include pharmaceutically acceptable salts, especially acid addition pharmaceutically acceptable salts.
One particular class of compounds of formula (1) is that wherein g is zero.
In the compounds according to the invention the group Ar1 is preferably a phenyl or monocyclic heteroaromatic group. Particularly useful groups of this type are five- or six-membered heteroaromatic groups as described previously, especially five- or six-membered heteroaromatic groups containing one or two heteroatoms selected from oxygen, sulphur or nitrogen atoms. Nitrogen-containing groups are especially useful, particularly pyridyl or pyrimidinyl groups.
A particularly useful group of compounds according to the invention has the formula (2): 
wherein R1 and R2, which may be the same or different is each an atom or group xe2x80x94L2(Alk3)tL3(R7)u in which L2, Alk3, t, L3, R7 and u are as defined formula (1) provided that R1 and R2 are not both hydrogen atoms;
Alk1, Alk2, m, r, g, L1, R4, R5, R6, Ra, Ar2 and R are as defined for formula (1);
and the salts, solvates, hydrates and N-oxides thereof.
R1 and R2 in compounds of formula (2) and in general in compounds of formula (1) is each preferably as particularly described above for compounds of formula (1), other than a hydrogen atom. Particularly useful R1 and R2 substituents include halogen atoms, especially fluorine or chlorine atoms, or methyl, halomethyl, especially xe2x80x94CF3, xe2x80x94CHF2 or xe2x80x94CH2F, methoxy or halomethoxy, especially xe2x80x94OCF3, xe2x80x94OCHF2 or xe2x80x94OCH2F groups.
R3 in compounds of the invention is in particular a hydrogen atom.
R in the compounds of formulae (1) and (2) is preferably a xe2x80x94CO2H group.
When present, the aliphatic chain represented by Alk1 in compounds of formulae (1) and (2) is preferably a xe2x80x94CH2xe2x80x94 chain.
In general in compounds of formulae (1) and (2) xe2x80x94(Alk1)rL1xe2x80x94 is preferably xe2x80x94CH2Oxe2x80x94 or xe2x80x94CON(R11)xe2x80x94. A particularly useful group is xe2x80x94CONHxe2x80x94.
In compounds of formulae (1) and (2) m is preferably 1 and Alk2 is preferably xe2x80x94CH2xe2x80x94; g in these compounds is preferaly zero.
R4 and R5 in the compounds of formulae (1) and (2) may be the same or different and is each preferably a hydrogen or halogen atom or an alkyl, alkoxy, hydroxy, nitro, cyano or xe2x80x94NR8R9 group.
R6 and Ra in the compounds of formulae (1) and (2) is each preferably a hydrogen atom.
Particularly useful classes of compounds according to the invention are those wherein Ar2 is an optionally substituted monocyclic aromatic or heteroaromatic group. One especially useful aromatic group when represented by Ar2 is phenyl. Especially useful heteroaromatic groups represented by Ar2 include optionally substituted monocyclic nitrogen-containing heteroaromatic groups, particularly optionally substituted pyridyl, pyrimidinyl, pyridazinyl and triazinyl groups. Where the group is a triazinyl group it is preferably a 1,3,5 triazine.
Optional substituents which may be present on preferred Ar2 aromatic or heteroaromatic groups include for example one or two substituents selected from those R13 substituents described above.
Particularly useful R13 substituents of these types include a halogen atom, especially fluorine or chlorine, morpholinyl, thiomorpholinyl, optionally substituted piperidinyl, especially piperidinyl or 4-carboxypiperidinyl, pyrrolidinyl, optionally substituted piperazinyl, especially t-butyloxycarbonylpiperazinyl, thioC1-6alkyl, especially thiomethyl, thioethyl or thiopropyl, optionally substituted thiobenzyl, especially thiobenzyl, haloC1-6alkyl, especially trifluoromethyl, C1-6alkyloxy, especially methoxy, ethoxy or propoxy, optionally substituted benzyloxy, especially benzyloxy, haloC1-6alkoxy, especially trifluoromethoxy and difluoromethoxy, C1-6alkylamino, especially methylamino, ethylamino or propylamino, C1-6dialkylamino, especially dimethylamino or diethylamino, optionally substituted C6-12arylC1-6alkylamino, especially benzylamino, 4-substituted benzyl, especially 4-fluorobenzylamino or 4-hydroxyphenylethylamino, aminoalkylamino, especially 3-aminopropylamino, Het1NC1-6alkylamino, especially 3-morpholinopropylamino, optionally substituted phenoxy, especially phenoxy, hydroxyC1-6alkylamino, especially 2-hydroxyethylamino, 3-hydroxypropylamino and 3-hydroxybutylamino, nitro, carboxyl, xe2x80x94CO2Alk5 [where R5 is as defined above], especially carboxymethyl and carboxyethyl, carboxamido, C1-6alkylaminocarbonyl, especially methylaminocarbonyl, ethylaminocarbonyl and propylaminocarbonyl, C1-6dialkylaminocarbonyl, especially dimethylaminocarbonyl, diethylaminocarbonyl or dipropylaminocarbonyl, C1-6alkanoyl, especially acetyl, propyryl or butyryl, optionally substituted benzoyl, especially benzoyl, C1-6alkylsulphinyl, especially methylsulphinyl, ethylsulphinyl or propylsulphinyl, C1-6alkylsulphonyl, especially methylsulphonyl, ethylsulphonyl, propylsulphonyl, hexylsulphonyl or isobutylsulphonyl, C1-6alkylaminosulphonyl, especially ethylaminosulfonyl or propylaminosulphonyl, C1-6dialkylaminosulphonyl, especially diethylaminosulphonyl, C1-6alkylaminocarbonyl, especially methylaminocarbonyl, ethylaminocarbonyl or propylaminocarbonyl, C1-6dialkylaminocarbonyl, especially dimethylaminocarbonyl or diethylaminocarbonyl.
Particularly useful Alk4 groups when present in compounds of the invention include xe2x80x94CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94(CH2)2CH2xe2x80x94 xe2x80x94CH(CH3)CH2xe2x80x94 and xe2x80x94(CH2)3CH2xe2x80x94 groups.
Particularly useful compounds of the invention include:
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4,6-dimethoxy-1,3,5-triazin-2-ylamino)propanoic acid;
S-3-[(3,5-Dichloropyrid4-ylcarboxamido)phenyl]-2-(6-propylsulphonylpyrimidin-4-ylamino)propanoic acid;
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-propylsulphinylpyrimidin-4-ylamino)propanoic acid;
S-3-[3-Chloro-4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propanoic acid;
S-3-[3,5-dichloro-4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-diethylaminosulphonylpyrimidin-4-ylamino)propanoic acid;
S-3-[3-Chloro4-(3,5-dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-propylaminosulphonylpyrimidin-4-ylamino)propanoic acid;
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methoxy-2-methylsulphonylpyrimidin-4-ylamino)propanoic acid;
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methoxy-2-propylsulphonylpyrimidin-4-ylamino)propanoic acid;
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methylsulphonylpyrimidin-4-ylamino)propanoic acid;
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-methoxy-6-(2-hydroxyethylamino)-1,3,5-triazin-2-ylamino)propanoic acid;
S-3-[4-4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-methoxy-6-(4-carboxypiperidinyl)-1,3,5-triazin-2-ylamino)propanoic acid;
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(4-methoxy-6-piperazinyl-1,3,5-triazin-2-ylamino)propanoic acid;
S-3[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-methyl-2-propylsulphonylpyrimidin4-ylamino)propanoic acid;
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-benzylsulphonylpyrimidin-4-ylamino)propanoic acid;
S-3-[4-4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-carboxy-2-propylsulphonylpyrimid-4-ylamino)propanoic acid;
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(6-chloropyridazin-3-yl-amino)propanoic acid;
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylsulphonylpyrazin-2-ylamino)propanoic acid;
3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(3-propylsulphonylbenzeneamino)propanoic acid;
3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-chloro-4-propylsulphonylpyridin-2-ylamino)propanoic acid;
3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-carboxy-4-propylsulphonylpyridin-2-ylamino)propanoic acid;
S-3[-4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-(5-carboxy-4-trifluoromethylpyrimidin-2-ylamino)propanoic acid;
S-3-[4-(3,5-Dichloro-1-oxidopyridino-4-ylcarboxamido)phenyl]-2-(6-propylsulphonylpyrimidin-4-ylaminoamino)propanoic acid;
S-3-[4-(3,5-Dichloropyrid-4-ylcarboxamido)phenyl]-2-[4-methoxy-6-(3-hydroxypropyamino)1,3,5-triazin-2-ylamino]propanoic acid;
and the salts, solvates, hydrates and N-oxides thereof.
Compounds according to the invention are potent and selective inhibitors of xcex14 integrins. The ability of the compounds to act in this way may be simply determined by employing tests such as those described in the Examples hereinafter.
The compounds are of use in modulating cell adhesion and in particular are of use in the prophylaxis and treatment of diseases or disorders involving inflammation in which the extravasation of leukocytes plays a role and the invention extends to such a use and to the use of the compounds for the manufacture of a medicament for treating such diseases or disorders.
Diseases or disorders of this type include inflammatory arthritis such as rheumatoid arthritis vasculitis or polydermatomyositis, multiple sclerosis, allograft rejection, diabetes, inflammatory dermatoses such as psoriasis or dermatitis, asthma and inflammatory bowel disease.
For the prophylaxis or treatment of disease the compounds according to the invention may be administered as pharmaceutical compositions, and according to a further aspect of the invention we provide a pharmaceutical composition which comprises a compound of formula (1) together with one or more pharmaceutically acceptable carriers, excipients or diluents.
Pharmaceutical compositions according to the invention may take a form suitable for oral, buccal, parenteral, nasal, topical or rectal administration, or a form suitable for administration by inhalation or insufflation.
For oral administration, the pharmaceutical compositions may take the form of, for example, tablets, lozenges or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g. pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g. lactose, microcrystalline cellulose or calcium hydrogen phosphate); lubricants (e.g. magnesium stearate, talc or silica); disintegrants (e.g. potato starch or sodium glycollate); or wetting agents (e.g. sodium lauryl sulphate). The tablets may be coated by methods well known in the art. Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents, emulsifying agents, non-aqueous vehicles and preservatives. The preparations may also contain buffer salts, flavouring, colouring and sweetening agents as appropriate.
Preparations for oral administration may be suitably formulated to give controlled release of the active compound.
For buccal administration the compositions may take the form of tablets or lozenges formulated in conventional manner.
The compounds for formula (1) may be formulated for parenteral administration by injection e.g. by bolus injection or infusion. Formulations for injection may be presented in unit dosage form, e.g. in glass ampoule or multi dose containers, e.g. glass vials. The compositions for injection may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilising, preserving and/or dispersing agents. Alternatively, the active ingredient may be in powder form for constitution with a suitable vehicle, e.g. sterile pyrogen-free water, before use.
In addition to the formulations described above, the compounds of formula (1) may also be formulated as a depot preparation. Such long acting formulations may be administered by implantation or by intramuscular injection.
For nasal administration or administration by inhalation, the compounds for use according to the present invention are conveniently delivered in the form of an aerosol spray presentation for pressurised packs or a nebuliser, with the use of suitable propellant, e.g. dichlorodifluoromethane, trichloroflouromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas or mixture of gases.
The compositions may, if desired, be presented in a pack or dispenser device which may contain one or more unit dosage forms containing the active ingredient. The pack or dispensing device may be accompanied by instructions for administration.
The quantity of a compound of the invention required for the prophylaxis or treatment of a particular condition will vary depending on the compound chosen, and the condition of the patient to be treated. In general, however, daily dosages may range from around 100 ng/kg to 100 mg/kg e.g. around 0.01 mg/kg to 40 mg/kg body weight for oral or buccal administration, from around 10 ng/kg to 50 mg/kg body weight for parenteral administration and around 0.05 mg to around 1000 mg e.g. around 0.5 mg to around 1000 mg for nasal administration or administration by inhalation or insufflation.
The compounds of the invention may be prepared by a number of processes as generally described below and more specifically in the Examples hereinafter. In the following process description, the symbols R1-R6, Ar1, L1, Alk1, Alk2, m, r, g, Ar2, Ra and R when used in the formulae depicted are to be understood to represent those groups described above in relation to formula (1) unless otherwise indicated. In the reactions described below, it may be necessary to protect reactive functional groups, for example hydroxy, amino, thio or carboxy groups, where these are desired in the final product, to avoid their unwanted participation in the reactions. Conventional protecting groups may be used in accordance with standard practice [see, for example, Green, T. W. in xe2x80x9cProtective Groups in Organic Synthesisxe2x80x9d, John Wiley and Sons, 1991]. In some instances, deprotection may be the final step in the synthesis of a compound of formula (1) and the processes according to the invention described hereinafter are to be understood to extend to such removal of protecting groups. For convenience the processes described below all refer to a preparation of a compound of formula (1) but clearly the description applies equally to the preparation of compounds of formula (2).
Thus according to a further aspect of the invention, a compound of formula (1) in which R is a xe2x80x94CO2H group may be obtained by hydrolysis of an ester of formula (3): 
where Rb is an alkyl group, for example a C1-6alkyl group as described above.
The hydrolysis may be performed using either an acid or a base depending on the nature of Rb, for example an organic acid such as trifluoroacetic acid or an inorganic base such as lithium or potassium hydroxide optionally in an aqueous organic solvent such as an amide, e.g. a substituted amide such as dimethylformamide, an ether, e.g. a cyclic ether such as tetrahydrofuran or dioxane or an alcohol, e.g. methanol at around ambient temperature. Where desired, mixtures of such solvents may be used.
Esters of formula (3) may be prepared by coupling an amine of formula (4): 
or a salt thereof with a reagent Ar2X1 where X1 is a leaving group. Particular leaving groups represented by X1 include for example halogen atoms such as fluorine, chlorine or bromine atoms or sulphonyloxy groups such as a methylsulphonyloxy group.
The coupling reaction may be performed using standard conditions for reactions of this type. Thus for example the reaction may be carried out in a solvent, for example an alcohol, e.g. methanol or ethanol, at a temperature from around ambient to the reflux temperature, optionally in the presence of a base, e.g. an organic base such as an amine, e.g. triethylamine or N,N-diisopropylethylamine, or a cyclic amine, such as N-methylmorpholine or pyridine.
In a further example compounds of formula (4) [Ra, R6 are H, g is zero] can be converted into compounds of formula (5) by treatment with nitrous acid, or isoamyl nitrite in the presence of an acid source, for example acetic acid, in a halogenated hydrocarbon e.g. dichloromethane or chloroform at a temperature from ambient temperature to 60xc2x0 C. 
Esters of formula (3) can be obtained from diazo compounds of formula (5) by reaction with amines of formula Ar2RaNH optionally in the presence of a catalyst, for example a rhodium (II) catalyst, for example rhodium (II) acetate dimer, a copper (II) catalyst, for example copper (II) acetate or a palladium (II) catalyst, for example palladium (II) acetate in an organic solvent, e.g. toluene, at a temperature from around ambient to the reflux temperature.
Where desired, compounds of formula (4) may be linked to a suitable solid support, for example via their carboxylate group (Rb is H), and subsequently converted to compounds of formula (1) linked to the solid support via the methods just described. Displacement from the resin by any convenient method for example by cleavage using an acid such as trifluoroacetic acid, then gives the desired compound of formula (1).
Particular examples of such solid-phase syntheses are given in the Examples herein.
The amines of formula (4) may be obtained from simpler, known compounds by one or more standard synthetic methods employing Cxe2x80x94C bond formation substitution, 1,4-addition, oxidation, reduction or cleavage reactions. Particular Cxe2x80x94C bond forming reactions include the Horner-Emmons and Wittig reactions. Particular substitution approaches include conventional alkylation, arylation, heteroarylation, acylation, thioacylation, halogenation, sulphonylation, nitration, formylation and coupling procedures. It will be appreciated that these methods may also be used to obtain or modify other compounds of formulae (1) and (2) where appropriate functional groups exist in these compounds. Additionally, although a number of the intermediates Ar2X1 for use in the coupling reaction described above are known, others can be derived therefrom using these standard synthetic methods.
Thus compounds of the invention and intermediates thereto may be prepared by alkylation, arylation or heteroarylation. For example, compounds containing a xe2x80x94L1 H, xe2x80x94L2H, or xe2x80x94L3H group (where L1, L2 and L3 is each a linker atom or group) may be treated with an alkylating agent: 
(R7)uL3Alk3tX2 or R7aX2 respectively in which X2 is a leaving atom or group such as a halogen atom, e.g. a fluorine, bromine, iodine or chlorine atom or a sulphonyloxy group such as an alkylsulphonyloxy, e.g. trifluoromethylsulphonyloxy or arylsulphonyloxy, e.g. p-toluenesulphonyloxy group, and R7a is an alkyl group.
The reaction may be carried out in the presence of a base such as a carbonate, e.g. caesium or potassium carbonate, an alkoxide, e.g. potassium t-butoxide, or a hydride, e.g. sodium hydride, in a dipolar aprotic solvent such as an amide, e.g. a substituted amide such as dimethylformamide or an ether, e.g. a cyclic ether such as tetrahydrofuran.
In another example, compounds containing a xe2x80x94L1 H, xe2x80x94L2H or xe2x80x94L3H group as defined above may be functionalised by acylation or thioacylation, for example by reaction with one of the alkylating agents just described but in which X2 is replaced by a xe2x80x94C(O)X3, C(S)X3, xe2x80x94N(R8)COX3 or xe2x80x94N(R8)C(S)X3 group in which X3 is a leaving atom or group as described for X2. The reaction may be performed in the presence of a base, such as a hydride, e.g. sodium hydride or an amine, e.g. triethylamine or N-methyl-morpholine, in a solvent such as a halogenated hydrocarbon, e.g. dichloromethane or carbon tetrachloride or an amide, e.g. dimethyl-formamide, at for example ambient temperature. Alternatively, the acylation or thioacylation may be carried out under the same conditions with an acid or thioacid (for example one of the alkylating agents described above in which X2 is replaced by a xe2x80x94CO2H or xe2x80x94COSH group) in the presence of a condensing agent, for example a diimide such as 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide or N,Nxe2x80x2-dicyclohexylcarbodiimide, advantageously in the presence of a catalyst such as a N-hydroxy compound e.g. a N-hydroxytriazole such as 1-hydroxybenzotriazole. Alternatively the acid may be reacted with a chloroformate, for example ethylchloroformate, prior to the desired acylation reaction
In a further example compounds may be obtained by sulphonylation of a compound containing an xe2x80x94OH group by reaction with one of the above alkylating agents but in which X2 is replaced by a xe2x80x94S(O)Hal or xe2x80x94SO2Hal group in which Hal is a halogen atom such as chlorine atom] in the presence of a base, for example an inorganic base such as sodium hydride in a solvent such as an amide, e.g. a substituted amide such as dimethylformamide at for example ambient temperature.
In another example, compounds containing a xe2x80x94L1H, xe2x80x94L2H or xe2x80x94L3H group as defined above may be coupled with one of the alkylation agents just described but in which X2 is replaced by an xe2x80x94OH group in a solvent such as tetrahydrofuran in the presence of a phosphine, e.g. triphenylphosphine and an activator such as diethyl, diisopropyl- or dimethylazodicarboxylate.
In a further example, ester groups xe2x80x94CO2R8 or xe2x80x94CO2Alk5 in the compounds may be converted to the corresponding acid [xe2x80x94CO2H] by acid- or base-catalysed hydrolysis depending on the nature of the groups R8 or Alk5. Acid- or base-catalysed hydrolysis may be achieved for example by treatment with an organic or inorganic acid, e.g. trifluoroacetic acid in an aqueous solvent or a mineral acid such as hydrochloric acid in a solvent such as dioxan or an alkali met al hydroxide, e.g. lithium hydroxide in an aqueous alcohol, e.g. aqueous methanol.
In a further example, xe2x80x94OR8 or xe2x80x94OR14 groups [where R8 or R14 each represents an alkyl group such as methyl group] in compounds of formula (1) may be cleaved to the corresponding alcohol xe2x80x94OH by reaction with boron tribromide in a solvent such as a halogenated hydrocarbon, e.g. dichloromethane at a low temperature, e.g. around xe2x88x9278xc2x0 C.
Alcohol [xe2x80x94OH] groups may also be obtained by hydrogenation of a corresponding xe2x80x94OCH2R14 group (where R14 is an aryl group) using a metal catalyst, for example palladium on a support such as carbon in a solvent such as ethanol in the presence of ammonium formate, cyclohexadiene or hydrogen, from around ambient to the reflux temperature. In another example, xe2x80x94OH groups may be generated from the corresponding ester [xe2x80x94CO2Alk5 or CO2R8] or aldehyde [xe2x80x94CHO] by reduction, using for example a complex met al hydride such as lithium aluminium hydride or sodium borohydride in a solvent such as methanol.
In another example, alcohol xe2x80x94OH groups in the compounds may be converted to a corresponding xe2x80x94OR8 group by coupling with a reagent R8OH in a solvent such as tetrahydrofuran in the presence of a phosphine, e.g. triphenylphosphine and an activator such as diethyl-, diisopropyl-, or dimethylazodicarboxylate.
Aminosulphonylamino [xe2x80x94NHSO2NH2] groups in the compounds may be obtained, in another example, by reaction of a corresponding amine [xe2x80x94NH2] with sulphamide in the presence of an organic base such as pyridine at an elevated temperature, e.g. the reflux temperature.
In a further example amine (xe2x80x94NH2) groups may be alkylated using a reductive alkylation process employing an aldehyde and a borohydride, for example sodium triacetoxyborohyride or sodium cyanoborohydride, in a solvent such as a halogenated hydrocarbon, e.g. dichloromethane, a ketone such as acetone, or an alcohol, e.g. ethanol, where necessary in the presence of an acid such as acetic acid at around ambient temperature.
In a further example, amine [xe2x80x94NH2] groups in compounds of formula (1) may be obtained by hydrolysis from a corresponding imide by reaction with hydrazine in a solvent such as an alcohol, e.g. ethanol at ambient temperature.
In another example, a nitro [xe2x80x94NO2] group may be reduced to an amine [xe2x80x94NH2], for example by catalytic hydrogenation using for example hydrogen in the presence of a metal catalyst, for example palladium on a support such as carbon in a solvent such as an ether, e.g. tetrahydrofuran or an alcohol e.g. methanol, or by chemical reduction using for example a metal, e.g. tin or iron, in the presence of an acid such as hydrochloric acid.
Aromatic halogen substituents in the compounds may be subjected to halogen-metal exchange with a base, for example a lithium base such as n-butyl or t-butyl lithium, optionally at a low temperature, e.g. around xe2x88x9278xc2x0 C., in a solvent such as tetrahydrofuran and then quenched with an electrophile to introduce a desired substituent. Thus, for example, a formyl group may be introduced by using dimethylformamide as the electrophile; a thiomethyl group may be introduced by using dimethyldisulphide as the electrophile.
In another example, sulphur atoms in the compounds, for example when present in a linker group L1, L2 or L3 may be oxidised to the corresponding sulphoxide or sulphone using an oxidising agent such as a peroxy acid, e.g. 3-chloroperoxybenzoic acid, in an inert solvent such as a halogenated hydrocarbon, e.g. dichloromethane, at around ambient temperature.
N-oxides of compounds of formula (1) may be prepared for example by oxidation of the corresponding nitrogen base using an oxidising agent such as hydrogen peroxide in the presence of an acid such as acetic acid, at an elevated temperature, for example around 70xc2x0 C. to 80xc2x0 C., or alternatively by reaction with a peracid such as peracetic acid in a solvent, e.g. dichloromethane, at ambient temperature.
Salts of compounds of formula (1) may be prepared by reaction of a compound of formula (1) with an appropriate base in a suitable solvent or mixture of solvents e.g. an organic solvent such as an ether e.g. diethylether, or an alcohol, e.g. ethanol using conventional procedures.
Where it is desired to obtain a particular enantiomer of a compound of formula (1) this may be produced from a corresponding mixture of enantiomers using any suitable conventional procedure for resolving enantiomers.
Thus for example diastereomeric derivatives, e.g. salts, may be produced by reaction of a mixture of enantiomers of formula (1) e.g. a racemate, and an appropriate chiral compound, e.g. a chiral base. The diastereomers may then be separated by any convenient means, for example by crystallisation and the desired enantiomer recovered, e.g. by treatment with an acid in the instance where the diastereomer is a salt.
In another resolution process a racemate of formula (1) may be separated using chiral High Performance Liquid Chromatography. Alternatively, if desired a particular enantiomer may be obtained by using an appropriate chiral intermediate in one of the processes described above.
Chromatography, recrystalliation and other conventional separation procedures may also be used with intermediates or final products where it is desired to obtain a particular geometric isomer of the invention.
The following Examples illustrate the invention. All temperatures are in xc2x0 C. The following abbreviations are used:
A solution of 3,5-dichloropyridine (5.00 g, 33.8 mmol) in THF (25 ml) was added to a solution of LDA [generated from nBuLi (2.5M solution hexanes, 14.9 ml, 37.2 mmol) and diisopropylamine (4.10 g, 5.7 ml, 40.6 mmol)] in THF (25 ml) at xe2x88x9278xc2x0 then CO2 gas was bubbled through to give a clear brown solution that slowly gave a precipitate, warmed to room temperature over 2 h, then quenched with water (20 ml) and partitioned between diethylether (100 ml) and 1M NaOH (100 ml). The aqueous layer was separated and acidified to pH1 with concentrated hydrochloric acid and then extracted with 10% MeOH in DCM (100 mlxc3x973). The combined organic layers were dried (MgSO4) and the solvent removed in vacuo to give a brown solid that was recrystallised from ethanol and dried under vacuum to give the title compound as pinkish crystals (2.63 g, 41%): xcex4H (DMSO d6) 8.72 (2H, s).
A slurry of Intermediate 1 (51.2 g, 0.267 mol) in DCM (195 ml) and thionyl chloride (195 ml, 2.67 mol) was treated with DMF (5 drops) and heated to reflux for 4 h. The reaction was concentrated in vacuo and azeotroped with toluene (2xc3x9750 ml) to give the acid chloride derivative of intermediate 1 as a yellow solid which was used without further purification. A solution of (S)-ethyl-3-(4-aminophenyl)-2-(t-butoxycarbonylamino)propionate (130.8 g, 0.425 mol) in DCM (800 ml) was cooled to 0xc2x0 and treated with NMM (56.0 ml, 0.51 mol), stirred 5 minutes and then a solution of the acid chloride (98.3 g, 0.468 mol) in DCM (200 ml) was added dropwise keeping the reaction temperature below 5xc2x0. The reaction was stirred for 1 h, quenched with NaHCO3 solution (500 ml), the organic layer separated, washed with NaHCO3 solution (500 ml), 10% citric acid solution (500 ml) and NaHCO3 solution (500 ml), dried (MgSO4) and concentrated in vacuo to give a yellow solid which was recrystallised (EtOAc/Hexane) to give the title compound (140 g, 69%): xcex4H (DMSO d6) 8.80 (2H, s), 7.55 (2H, d, J 8.5 Hz), 7.23 (2H, d, J 8.5 Hz), 4.00 (3H, m), 3.40 (2H, br. s), 2.90 (1 H, m), 2.80 (1H, m), 1.30 (9H, s), 1.25 (3H, t); m/z (El+, 70V) 504.
A solution of Intermediate 2 (70.0 g, 0.146 mol) in EtOAc (500 ml) and 1,4-dioxan (50 ml) was treated with a solution of HCl in EtOAc (500 ml, 3M), and stirred at room temperature for 4 h. The reaction was concentrated in vacuo to give a yellow soild which was triturated with Et2O then recrystallised (EtOAc/hexane) to give the title compound (59.3 g, 92%): xcex4H (DMSO d6) 11.10 (1H, s), 8.70 (2H, s), 7.55 (2H, d, J 8.4 Hz), 7.25 (2H, d, J 8.4 Hz), 4.10 (3H, m), 3.10 (2H, m), 1.10 (3H, m); m/z (El+, 70V) 382.
The title compound was prepared in a similar manner to Intermediate 3 starting from (S)-methyl-3-(4-aminophenyl)-2-(t-butoxycarbonylamino) propionate and Intermediate 1: xcex4H (DMSO d6) 11.08 (1H, s), 8.77 (2H, s), 8.73 (3H, br. m), 7.63 (2H, d, J 8.5 Hz), 7.25 (2H, d, J 8.5 Hz), 4.24 (1H, m), 3.70 (3H, s), 3.16 (2H, m); m/z (El+, 70V) 368 and 370.
A solution of 3,5-dichloropyridine-4-carboxaldehyde (1.34 g, 7.6 mmol) in MeOH (10 ml) was treated with NaBH4 (0.29 g, 7.6 mmol) and stirred at room temperature for 2 h. The reaction was quenched with water (5 ml) and concentrated in vacuo. The residue was partitioned between EtOAc (20 ml) and 10% HCl (10 ml). The aqueous layer was extracted with EtOAc and the combined organic extracts washed with 10% NaHCO3 solution, dried (MgSO4) and concentrated in vacuo to give the title compound as a white solid (1.05 g, 78%): xcex4H (CDCl3) 8.52 (2H, s), 4.94 (2H, br. s), 2.28 (1H, br. s).
A solution of Intermediate 5 (0.50 g, 2.80 mmol) in DCM (10 ml) was treated with thionyl bromide (3.51 g, 1.32 ml, 16.9 mmol) and heated to reflux for 3 h. The reaction was quenched with 10% NaHCO3 solution (10 ml) and extracted with DCM (25 ml). The organic layer was dried (MgSO4) and concentrated in vacuo to give the title compound as a yellow oil that solidified on standing (0.65 g, 96%) and was used without further purification: xcex4H (CDCl3) 8.50 (2H, s), 4.63 (2H, s); m/z (El+, 60V) 242.
The title compound was obtained by reaction of N-Boc-L-tyrosine ethyl ester with Intermediate 6 in the presence of sodium hydride, followed by Boc deprotection, using methods well known to a person skilled in the art: xcex4H (DMSO d6) 8.79-8.60 (3H, m), 7.20 (2H, d, J 8.6 Hz), 7.00 (2H, d, J 8.6 Hz), 5.21 (2H, s), 4.34-4.20 (1 H, m), 3.67 (3H, s); m/z (El+, 70V) 355 and 357.
A solution of 4-nitro-L-phenylalanine ethyl ester (3.22 g, 13.53 mmol), DIPEA (2.35 ml, 1.75 g, 13.56 mmol) and 4,6-dichloropyrimidine (2.02 g, 13.55 mmol) in absolute ethanol (16 ml) was stirred at 70xc2x0 for 18 h under N2. The volatiles were removed in vacuo and the residue partitioned between EtOAc (70 ml) and water (40 ml). The phases were separated and the aqueous phase re-extracted with EtOAc (2xc3x9730 ml). The combined organic extracts were washed with brine (10 ml), dried (Na2SO4) and evaporated in vacuo to afford a dark oil. Chromatography (silica, 2% MeOH/DCM) afforded the title compound as an orange oil which slowly solidified (4.03 g, 85%); xcex4H (CDCl3,) 8.39 (1H, s), 8.13 (2H, d, J 8.7 Hz), 7.28 (2H, d, J 8.7 Hz), 6.43 (1H, s), 5.55 (1H, br d, J 7.0 Hz), 5.10-5.00 (1H, br m), 4.21 (2H, q, J 7.1 Hz), 3.27 (1H, dd, J 13.8, 6.0 Hz), 3.27 (1H, dd, J 13.8, 5.7 Hz) and 1.26 (3H, t, J 7.1 Hz); m/z (El+, 100V) 351.
A mixture of Intermediate 8 (1 g, 2.85 mmol) and 10% palladium on activated carbon (100 mg) in absolute ethanol (40 ml) was stirred under a hydrogen atmosphere (balloon) at room temperature for 1.5 h. After degassing and N2 flushing, the catalyst was removed by filtration through a Celite(copyright) pad and washed with DCM. The filtrate was evaporated in vacuo and the obtained yellow oil subjected to chromatorgaphy (silica: 3% MeOH/DCM). The title compound was isolated as a yellow oil (0.42 g, 46%) xcex4H (CDCl3) 8.33 (1H, s), 6.86 (2H, J, 8.4 Hz), 6.56 (2H, d, J 8.4 Hz), 6.30 (1H, s), 5.27 (1H, br s), 4.84 (1H, br s), 4.19 (2H, q, J 7.1 Hz), 3.64 (2H, br s), 3.10 (1H, dd, J 14.0, 5.6 Hz), 3.01 (1H, dd, J 14.0, 6.1 Hz) and 1.26 (3H, t, J 7.1 Hz); m/z (El+, 100V) 321.
Intermediate 3 (0.5 g, 1.19 mmol) in dry acetonitrile (5 ml) under nitrogen was added to 2,4 dichloro-6-methoxy-1,3,5-triazine (0.26 g, 1.43 mmol). The mixture was cooled to xe2x88x9230xc2x0 and DIPEA (0.46 ml) was added slowly over 10 min. The reaction was allowed to warm to 5xc2x0 over 2 h and then ethyl acetate and aqueous sodium bicarbonate were added and the mixture shaken and separated. The organic layer was washed with water, dried (MgSO4) and the solvent removed in vacuo. The product was purified by flash chromatography (silica ; EtOAC/Hexane 1:1) to afford the title compound as a white solid (0.53 g, 85%): xcex4H (DMSO d6) 10.55 (1H, s), 8.70 (2H, s), 8.51-8.40 (1H,m), 7.50 (2H, d, J 8.4 Hz), 7.29 (2H, d, J 8.4 Hz), 4.60 (1H, m), 4.12 (2H, d, J 8.4 Hz), 3.87 (3H, s), 3.23-3.15 (2H, m), 1.16 (3H, t, J 7.2 Hz); m/z (El+, 70V) 527.
A mixture of L-tyrosine ethyl ester hydrochloride (0.50 g, 2.0 mmol) and DIPEA (0.74 ml, 4.4 mmol) in CH3CN (8 ml) was stirred at room temperature for 15 minutes and then 2-chloro-4,6-dimethoxy-1,3,5-triazine (0.43 g, 2.2 mmol) was added, and the reaction stirred overnight then concentrated in vacuo. The residue was partitioned between EtOAc (50 ml) and NaHCO3 solution (50 ml). The organic layer was washed with 10% citric acid solution (50 ml), NaHCO3 solution (50 ml) and water (50 ml), dried (MgSO4) and concentrated in vacuo to give the title compound as a colourless gum (0.48 g, 68%): xcex4H (DMSO d6) 6.90 (2H, d), 6.65 (2H, d), 5.90 (1H, m), 4.90 (1H, m), 4.10 (2H, m), 3.95 (3H, s), 3.90 (3H, s), 3.10 (2H, m), 1.20 (3H, t, J 7.1 Hz); m/z (El+, 70V) 349.
Propanethiol (1.99 ml, 22 mmol) was added to a suspension of sodium hydride (60% in mineral oil, 880 mg, 22 mmol) in THF (50 ml). After 10 min, a solution of 2,3-dichloropyrazine (1.49 g, 10 mmol) in THF (15 ml) was added and the mixture stirred at room temperature overnight. The reaction was quenched with water and the solvent removed in vacuo. The residue was dissolved in EtOAc, washed with water, 10% NaOH solution and brine, dried (Na2SO4) and evaporated in vacuo to give a pale yellow oil (2.7 g). This was dissolved in DCM (100 ml) at 0xc2x0, and mCPBA (57-86%, xcx9c40 mmol, 12.1 g) was added in portions. The mixture was stirred at room temperature overnight, then treated with Na2SO3 (aq). The organic phase was washed with NaHCO3 (aq), dried (Na2SO4) and evaporated in vacuo to give the title compound as a white solid (3.18 g): xcex4H (CDCl3) 8.94 (2H, s), 3.68-3.63 (4H, m), 2.10-1.88 (4H, m), 1.10 (6H, t, J 7.4 Hz); m/z (El+, 70V) 293.
The title compound was prepared by the method of Intermediate 12 from 4,6-dichloropyrimidine: xcex4H (DMSO d6) 9.77 (1H, d, J 1.3 Hz), 8.40 (1H, d, J 1.3 Hz), 3.61-3.56 (4H, m), 1.75-1.65 (4H, m), 0.97 (6H, t, J 7.5 Hz); m/z (El+, 70V) 293.
A solution of phenol (564 mg, 6 mmol) in THF (5 ml) was added to a suspension of sodium hydride (60% in mineral oil, 240 mg, 6 mmol) in THF (10 ml). After 10 min 2,3-dichloroquinoxaline (995 mg, 5 mmol) was added. The mixture was stirred for 3 days. The solvent was removed in vacuo, the residue was dissolved in EtOAc, washed with NaOH (1M), dried (Na2SO4) and evaporated in vacuo to give a yellow solid. Recrystallisation from diisopropylether gave the title compound as off-white needles: xcex4H (DMSO d6) 8.01-7.98 (1H, m), 7.77-7.67 (3H, m), 7.53-7.48 (2H, m), 7.37-7.30 (3H, m); m/z (El+, 70V) 257.
Ethyl 2-(diethoxyphosphoryl)acetate (5.0 ml, 25.2 mmol) was added to a suspension of sodium hydride (60% in mineral oil, 1.10 g, 27.6 mmol) in THF (40 ml) at 0xc2x0. After 30 min at room temperature, a solution of 4-nitrobenzylbromide (5.42 g, 25.2 mmol) in THF (40 ml) was added over 30 min. The reaction mixture was stirred for 2 h at room temperature, quenched with water and partitioned between Et2O and water. The aqueous phase was extracted with Et2O and the combined organic layers washed with brine, dried (MgSO4) and evaporated in vacuo. Column chromatography (silica; MeOH/DCM, 1:49) gave the title compound as a pale yellow oil (2.01 g): xcex4H (CDCl3) 8.13 (2H, d, J 8.8 Hz), 7.37 (2H, d, J 8.8 Hz), 4.23-4.06 (6H, m), 3.37-3.20 (3H, m), 1.35 (6H, t, J 7.1 Hz), 1.16 (3H, t, J 7.1 Hz): m/z (El+, 70V) 360.
A mixture of Intermediate 15 (4.5 g, 12.0 mmol) and tin(II) chloride dihydrate (15 g) in ethanol was stirred overnight. The solvent was removed in vacuo. DCM (100 ml) and 1M NaOH (100 ml) was added and the white precipitate removed by filtration. The organic phase of the filtrate was separated and evaporated in vacuo. The residue was acidified to pH1 with dil. HCl and extracted with diethyl ether. The aqueous phase was basified to pH10 with Na2CO3 and extracted with EtOAc. The EtOAc extracts were dried (MgSO4) and evaporated in vacuo. Column chromatography (silica; MeOH/DCM 5:95) gave the title compound as a yellow oil (2.19 g): xcex4H (CDCl3) 6.98 (2H, d, J 8.2 Hz), 6.59 (2H, d, J 8.5 Hz), 4.22-4.04 (6H, m), 3.25-3.02 (3H, m), 1.34 (6H, m), 1.16 (3H, t, J 7.1 Hz): m/z (El+, 70V) 330.
A solution of 3,5-dichloropyrid-4-ylcarbonyl chloride (1.41 g, 6.7 mmol) in THF (10 ml) was added to a solution of Intermediate 16 (2.19 g, 6.7 mmol) and NMM (0.88 ml, 8.0 mmol) in THF (40 ml). The mixture was stirred at room temperature overnight then partitioned between EtOAc and water. The aqueous layer was extracted with EtOAc and the combined organic layers washed with 10% aqueous HCl and NaHCO3 (aq), dried (MgSO4) and evaporated in vacuo. Column chromatography (silica; MeOH/DCM 5:95) gave the title compound as a yellow oil (2.61 g): xcex4H (CDCl3) 8.55 (2H, s), 8.08 (1H, br. s), 7.55 (2H, d, J 8.5 Hz), 7.21 (2H, d, J 8.5 Hz), 4.19-4.08 (6H, m), 3.25-3.10 (3H, m), 1.35 (3H, t, J 7.1 Hz), 1.34 (3H, t, J 7.1 Hz), 1.18 (3H, t, J 7.1 Hz).
A mixture of Intermediate 17 (1.74 g, 3.6 mmol), potassium carbonate (1.48 g, 10.7 mmol) and aqueous paraformaldehyde (37% wt, 10 ml) was heated at reflux for 4 h. The mixture was partitioned between EtOAc and water. The aqueous phase was extracted with EtOAc and the combined organic layers washed with brine, dried (MgSO4) and evaporated in vacuo. Column chromatography (silica; EtOAc/Hexane 50:50) gave the title compound as a white solid (1.09 g): xcex4H (CDCl3) 8.52 (1H, br. s), 8.44 (2H, br. s), 7.49 (2H, d, J, 8.5 Hz), 7.18 (2H, d, J 8.5 Hz), 6.22 (1H, br. s), 5.49 (1H, br. s), 4.15 (2H, q, J 7.2 Hz), 3.60 (2H, br. s), 1.27 (3H, t, J 7.2 Hz).
A mixture of Intermediate 18 (1.50 g, 3.7 mmol) and liquid ammonia (10 ml) was kept in a sealed vessel for 3 d at room temperature. Column chromatography (silica; MeOH/DCM 1:9 to 1:4) gave the title compound as a colourless oil (1.00 g): xcex4H (DMSO d6) 10.83 (1H, s), 8.78 (2H, d, J 18.5 Hz), 7.54 (2H, d, J 8.5 Hz), 7.16 (2H, d, J 8.5 Hz), 4.00 (2H, q, J 7.1 Hz), 3.29 (2H, br. s), 2.83-2.61 (5H, m), 1.10 (3H, t, J 7.1 Hz): m/z (El+, 70V) 396.
A solution of the compound of Intermediate 3 (free amine) (2.80 g, 7.40 mmol), glacial acetic acid (1.4 ml, 24.50 mmol), isoamyl nitrite (1 ml, 7.40 mmol) in 100 ml anhydrous chloroform were stirred at reflux under nitrogen for 1 h. On cooling the solution was washed with water (2xc3x9725 ml), saturated NaHCO3 (2xc3x9725 ml), water (2xc3x9725 ml), dried (Na2SO4) and evaporated in vacuo to afford the title compound as a yellow solid (2.1 g, 100%): xcex4H (CDCl3) 8.56 (2H, s), 7.72 (1H, br. s), 7.55 (2H, d, J 8.5 Hz), 7.26 (2H, d, J 8.5 Hz), 4.22 (2H, q, J 7.1 Hz), 3.62 (2H, s), 1.25 (3H, t, J 7.1 Hz).
2-Amino-5-chloropyridine (10.0 g, 77 mmol), acetonyl acetone (8.8 g, 77 mmol) and a catalytic amount of p-toluenesulphonic acid in anhydrous toluene (250 ml) was heated to reflux for 5 h under Dean and Stark conditions. The solvent was removed in vacuo, the residue slurried in hexane (250 ml), filtered through celite and the solvent removed in vacuo to give the title compound as a yellow oil (16.0 g): xcex4H (CDCl3) 8.57 (1H, dd, J 2.7, 0.6 Hz), 7.78 (1H, dd, J 8.4, 2.7 Hz), 7.17 (1H, m, J 7.5, 0.5 Hz), 5.91 (2H, s), 2.14 (6H, s).
To a solution of LDA (12.3 mmol) in anhydrous toluene (6 ml) at xe2x88x9278xc2x0 under nitrogen was added Intermediate 21 (2.3 g, 11.2 mmol) in THF (6 ml) dropwise over 15 min. After stirring a further 15 min at this temperature n-propyl disulfide (1.92, 12.8 mmol) in THF (2 ml) was added dropwise maintaining the temperature at xe2x88x9278xc2x0. On completion of the addition the reaction was allowed to warm to room temperature and quenched with 10% NH4Cl solution, diluted with EtOAc (50 ml) and the phases separated. The organic phase was washed with water (2xc3x9710 ml), dried (MgSO4) and the solvent removed in vacuo. The residue was purified by chromatography (silica; 2% EtOAc/Hexane) to give the title compound (2.9 g) as a yellow solid: xcex4H (CDCl3) 8.39 (1H, s), 7.00 (1H, s), 5.92 (2H, s), 2.91 (2H, d, J 7.4 Hz), 2.15 (6H, s), 1.74 (2H, m), 1.09 (3H, t, J 7.4 Hz).
Intermediate 22 (1.3 g, 4.6 mmol) and hydroxylamine hydrochloride (1.6 g, 23 mmol) were heated to reflux in EtOH (12 ml) and water (3.5 ml) for 16 h. The cooled solution was poured onto conc HCl (12 ml)/water (48 ml) and the resulting solid filtered, washed with water and dried to give the title compound as a brown solid (550 mg): xcex4H (CDCl3) 8.11 (1H, s), 6.91 (1H, s), 3.01 (2H, t, J 7.3 Hz), 1.64 (2H, m), 1.00 (3H, t, J 7.3 Hz)): m/z (El+, 70V) 203.
Paramax Wang resin (Advanced Chemtech, 8.0 g, 0.69 mmol/g, 5.52 mmol equivalent) in DCM (100 ml) was treated with N-xcex1-FMOC-4-nitro-L-phenylalanine (11.93 g, 27.6 mmol), diisopropylcarbodiimide (4.32 ml, 27.6 mmol) and 4-N,N-dimethylaminopyridine (0.67 g, 5.52 mmol) and mixture was agitated at room temperature for 16 h. The resin was filtered and washed with DMF, methanol and DCM, then air-dried. The resin was then treated with stannous chloride dihydrate (12.5 g, 55.2 mmol) in DMF (100 ml) at room temperature for 6 h, washed with DMF, methanol and DCM, then air dried overnight. The resin was treated with pyridine (4.44 ml, 55.2 mmol), 3,5-dichloropyrid-4-carbonyl chloride 3.52 g, 16.56 mmol) and 4-N,N-dimethylamino pyridine (0.67 g, 5.52 mmol) in DCM (100 ml). The reaction mixture was agitated at room temperature for 16 h. The resin was then washed with DMF, methanol and DCM, then with two 50 ml portions of a 10% solution of pyridine in DMF (100 ml). The resin was further washed with hot ethanol (2xc3x97100 ml), DMF, methanol and DCM then air-dried to give the title compound.
A portion of Intermediate 24 (3.0 g) was treated twice with a 20% solution of piperidine in DMF (100 ml), once for 5 min and once for 15 min. The resin was washed with DMF, methanol and DCM. This material was treated with isoamyl nitrite (1.79 ml, 12.30 mmols) and acetic acid (0.074 ml, 1.23 mmols) in anhydrous chloroform (70 ml) for 1 hr, then filtered and washed with DMF, methanol and DCM then finally air dried to give the title compound.